When observing a comet please try to forget how bright you think the comet
should be, what it was when you last viewed it, what other observers think
it is or what the ephemeris says it should be.

The equations for the light curves of comets that are currently visible
use only the raw observations and should give a reasonable prediction for
the current brightness. If the comet has not yet been observed or has
gone from view a correction for aperture is included, so that telescopic
observers should expect the comet to be fainter than given by the equation.
The correction is about 0.033 per centimetre. Values for the r parameter
given in square brackets [ ] are assumed. The form of the light curve is
either the standard m = H0 + 5 log d + K0 log r or the linear brightening
m = H0 + 5 log d + L0 abs(t - T + D0) where T is the date of perihelion,
t the present and D0 an offset, if L0 is +ve the comet brightens towards
perihelion and if D0 is +ve the comet is brightest prior to perihelion.

Observations of individual comets are given in ICQ format.

Full text of IAU Circular announcements will not be given until the circular
is publicly available.

J. Broughton, Reedy Creek, Queensland, writes that his CCD observations
(0.25-m f/6.6 Schmidt-Cassegrain) on May 9.3 UT showed the brighter (western)
component at m2 = 14.7, with the secondary, 0.3 mag fainter, perhaps 5"
distant in p.a. 100 deg, although some elongation of the secondary could make
the separation as much as 7". On May 10.3 the appearance was similar. On May
11.3 the western component had brightened to m2 = 13.2, and the eastern
component had virtually disappeared. On May 12.4 the western component had
faded to m2 about 14.0, while the secondary was then perhaps 2 mag fainter,
8".5 away in p.a. 100 deg.

Using the absolute astrometry for Apr. 30 (see IAUC 7616) and May 9
given on MPC 42656 (where the western primary is labeled B and the eastern
secondary is labeled A), Z. Sekanina, Jet Propulsion Laboratory, obtained
a separation time of Mar. 17 +/- 12 and an acceleration of 7.1 +/- 2.4 (in
units of 10**-5 solar gravity).

E. Jehin, A. Jaunsen, H. Boehnhardt, M. Kiekebusch, H. Nunez, R. Amestica,
C. Herrera, J. Navarete, F. Delgado and R. M. West, European Southern
Observatory, report: "Images of comet C/2001 A2 have been obtained using the
8.2-m Very Large Telescopes Melipal and Yepun with the Nasmyth and Cassegrain
test cameras, respectively. On May 14.98 UT two components were seen in R-band
images, the eastern, tailward one (component A) about 1 mag fainter than
component B (within an aperture of 1".3) at a separation of 12".6 in
p.a. 105 deg. Both components had individual comae elongated approximately
in the antisolar direction. Component B showed sunward-extended isophotes in
the very inner part of the coma. On May 16.98 UT the distance between the
components had increased to 14".6 (in the same position angle). In
addition, the sunward fragment appeared to have split into two components with
a separation of 1" in p.a. 135-315 deg; these components were of about the
same brightness (in R) and surrounded by a joint coma. V-band images revealed
very extended isophotes perpendicular to the separation direction of this new
pair. This could indicate the presence of a large amount of gas in the coma
in addition to the dust."

J. Broughton, Reedy Creek, Queensland (0.25-m Schmidt-Cassegrain),
reports further CCD astrometry on May 14.4 and 16.3 UT, noting that on the
latter occasion component A was at least two magnitudes fainter than and was
separated from component B by about 14" in p.a. 102 deg. [IAUC 7627, 2001 May 17]

L. M. Woodney and D. G. Schleicher, Lowell Observatory; and R.
Greer, Wittenberg University, report narrowband gas and dust
imaging of this comet: "On June 29-30, the comet displayed CN
jet(s) symmetrical about p.a. 250 deg. Three successive arcs
separated by approximately 12 000 km were observed on each side;
outward motion of the arcs was detected. These arcs were not
observed in the dust continuum." [IAUC 7666, 2001 July 18]

M. Kidger, Instituto de Astrofisica de Canarias, reports: "Monitoring
of the inner coma by the Spanish Comet Observers Team reveals two small
photometric events that are possibly related to the ejection of small
fragments from the nucleus. Representative CCD R magnitudes, using a 10"
aperture and the USNO A2.0 catalogue for reference stars: July 23.996 UT,
12.62 (R. Ferrando, Pla D'Arguines, 0.26-m Schmidt-Cassegrain); 24.889, 12.80
(P. Manteca, Begues, 0.26-m Schmidt-Cassegrain); 25.936, 12.4 (D. Rodriguez,
Madrid, 0.20-m Schmidt-Cassegrain); 29.853, 12.79 (Manteca); 30.933, 12.92
(Manteca); 31.881, 12.85 (Manteca); Aug. 2.896, 12.95 (Manteca); 3.844, 13.1
(Manteca); 7.84, 13.4 (R. Ligustri, Latisana, Italy, 0.2-m reflector); 7.852,
13.4 (Ferrando). The lightcurve indicates events of amplitude 0.4 and 0.2 mag
initiating at approximately July 25.0 and 30.0 respectively. For comparison,
the major event around July 12 (cf. IAUC 7659, 7676) had an amplitude of 1.5
mag (10" aperture). This indicates that, if due to fragmentation, these later
events were probably caused by the separation of small, short-lived splinters
that may not have been directly observable." [IAUC 7679, 2001 August 9]

P. D. Feldman, H. A. Weaver, and E. B. Burgh, Johns Hopkins
University, report observations of comet C/2001 A2 with the Far
Ultraviolet Spectroscopic Explorer beginning July 12.58 UT and
coinciding with the photometric event reported on IAUC 7679:
"Spectra (range 91-118 nm; spectral resolution 0.03 nm) were
obtained using the 30" x 30" aperture. Several new cometary
emissions were identified, particularly the (0,0) bands of the CO
Birge-Hopfield systems (C-X and B-X) at 108.8 and 115.1 nm,
respectively; O I [(^1)D-(^1)D] at 115.2 nm; and three lines of the
H_2 Lyman system at 107.16, 111.86, and 116.68 nm, pumped by solar
Lyman-beta fluorescence. Also detected were O I multiplets at
98.9, 102.7, and 104.0 nm, and several lines of the H I Lyman
series. The rotational envelopes of the CO bands are resolved and
appear to consist of both cold and warm components, the cold
component accounting for 80 percent of the flux and having a
rotational temperature of 60 K. The warm component may be
indicative of a CO_2 source. Both the CO bands and the O I
115.2-nm emission (an indicator of H_2O production) decreased by a
factor of two over the 7.5 hr observation. Preliminary estimates
of the production rates at the beginning of the observation are
Q(CO) = 4 x 10^(27) s^(-1) and Q(H_2O) = 3 x 10^(29) s^(-1)
(vectorial model). These values may be uncertain by as much as a
factor of two, due to uncertainties in the solar flux. No emission
is detected from Ar I at 104.8 and 106.7 nm and He I at 58.4 nm (in
second order). We derive Q(Ar) = 6 x 10^(25) s^(-1) (5-sigma
upper limit), which implies that Ar/O is more than a factor of ten
less than solar. In addition to the features listed above, more
than two dozen other emissions remain unidentified." [IAUC 7681, 2001
August 15]

A. Lecacheux, Observatoire de Paris, on behalf of the Odin
Team (http://www.snsb.se/Odin/Odin.html), reports: "The H_2O
110-101 line at 556.936 GHz was observed in C/2001 A2 with high
spectral resolution (54 m/s) with the ODIN submillimeter space
telescope from June 20 until July 12. From a preliminary analysis,
10' x 10' mapping made during July 1.5-2.4 UT shows that the H_2O
coma is elongated along the comet-sun line; the integrated line
intensity inside the 2' beam peaks at 12 K km s**-1, on the main-
beam brightness temperature scale. The line width indicates an
H_2O outflow velocity of 0.7 km/s. The estimated water-production
rate for July 1.7-2.0 is 3.8 x 10**28 molecules/s."
[IAUC 7706, 2001 September 6]

David Seargent reported a visual observation at 13.1 on March 14,
a little brighter than expected. It brightened very rapidly and reached
8th mag by the end of the month. It continued to brighten and
became more condensed as it approached the sun. An estimate by
Andrew Pearce on April 20.51 put it at 7.1 in 20x80B. Several estimates
on April 24 commented that the comet had brightened rapidly in the last 24
hours and was now around 6.5. By the end of April it had reached 6th mag, but during
early May the rate of brightening has slowed significantly, perhaps associated
with the nuclear splitting observed at the end of April. More rapid
brightening resumed around May 10 and the comet reached around 5th mag. An
obsevation from Michael Mattiazzo on May 17.42 put it at 5.2 in 7x50B with a tail at least
1.6 degrees long; the comet was also visible to the naked eye. As of May 21
it was still 5th mag. Andrew Pearce reported that the comet had brightened
to 4.8 on May 31.44 and the comet had a 1.5 degree long tail. The coma was
noticeably blue-green in colour. On June 11.91 Andrew reported further brightening,
estimating the comet at 3.6 to the naked eye and a 1.7 degree long tail in 20x80B.
Michael Mattiazzo photographed the comet on June 12.

Giovanni Sostero recovered the comet on June 27.
I picked it up on July 1.05 with 7x50B and estimated it at 5.3. It was an
easy object, well condensed and diameter 11'. On July 10.9 it was an easy
object in 8x30B of about mag 5.5, DC3 and diameter 12'. A further outburst
took place on July 12, and on July 12.95 it was just visible to the naked eye
from central Cambridge.

Michael Mattiazzo points out that the
orbital plane crossing took place around July 15-16th. From this, we may
expect enhancement of a dust tail in the solar and anti solar directions.

The comet is now fading quite rapidly and has become very diffuse, making it
a difficult object to pick out against the Milky Way background.
Observations in mid August put it at around 9th
magnitude, DC 1 - 2 and around 6' diameter. Observing on August 28.06 with my
0.20-m SCT x75 I made it 10.8, DC1 and diameter 2.3'

879 observations give a preliminary uncorrected light curve of
7.3 + 5 log d + 10.6 log r, with several small outbursts after the major one at
the end of March, another a week or so later and a third in mid June as can be seen in
the light curve. This also suggests that there was quasi-
periodic variation in the light curve with an amplitude of about a magnitude.

2001 B1 LINEAR
M. Blythe, Lincoln Laboratory, reports the discovery by LINEAR
of an apparent 17th magnitude comet on January 22.08.
Additional observations have been received
following posting on the NEO Confirmation Page. [IAUC 7570, 2001
January 24] The comet is in a distant parabolic orbit which reached
perihelion last September and it will fade.
2001 B2 NEAT
E. F. Helin, S. Pravdo, and K. Lawrence, Jet Propulsion
Laboratory, report that their CCD images of this comet taken on
Jan. 24.6 and 25.6 UT with the 1.2-m NEAT telescope at Haleakala
show a coma diameter of about 29"; there is no convincing evidence
for a tail, though some images suggest a certain asymmetry toward
the northwest. Additional astrometry is reported on MPEC 2001-B47
[IAUC 7573, 2001 January 27] The comet is distant, but should brighten
a little as it does not reach perihelion until June.

A/2001 BL41 (Spacewatch)
This 20th magnitude centaur type asteroid was discovered by Spacewatch on
January 19.30. It has a perihelion distance of 6.88 AU and a period of 30.7
years. It was at perihelion in February 1998.
2001 BB50 LINEAR-NEAT
S. Pravdo, K. Lawrence, and E. Helin, Jet Propulsion
Laboratory, reported the discovery of aN 18th mag comet on Mar. 20 CCD images
taken with the NEAT 1.2-m reflector at Haleakala, the object
showing a short eastward tail, a nuclear condensation of size < 3",
and a coma diameter of about 10". T. B. Spahr, Minor Planet Center,
linked this object first with an object reported as asteroidal by
LINEAR on Mar. 18 (m_2 = 19.5) and then to the LINEAR object 2001
BB_50, observed on Jan. 21 and 26 (MPS 25734). Following posting
on the NEO Confirmation Page, C. Jacques, Belo Horizonte, Brazil,
also reported a 10" coma and m_1 = 18.6 on CCD images taken on Mar.
21 (0.3-m reflector). Full astrometry and the orbital elements
appear on MPEC 2001-F26. [IAUC 7601, 2001 March 21] The comet has a
perihelion distance of 2.35AU and is intrinsically faint. Its period is
13.6 years.
2001 C1 LINEAR
L. Manguso, Lincoln Laboratory, reports the discovery of an
apparent 19th mag comet by LINEAR on February 1.48.
Confirming CCD observations by G. Hug
(Eskridge, KS) reveal a condensed coma and a suggestion of a faint,
broad tail in p.a. about 325 deg. [IAUC 7578, 2001 February 2] The
preliminary orbit suggests that the comet is in a distant parabolic
orbit and will not come within visual range.

S Nakano was able to link the comet with an asteroid 2000 HR81, first
observed by LONEOS on 2000 April 29.28. The new orbit, which is similar to
the preliminary one, shows that the comet
is a first time visitor to the inner solar system with 1/a (orig) of 0.000049.
[MPEC 2001-H23, 2001 April 21]

2001 C5 SOHO
Michael Oates discovered a 6th mag non Kreutz object on C2 images
on February 14. A retrograde orbit with perihelion distance of 0.026 AU
was published on MPEC 2001-D07 [2001 February 18], though Marsden notes
"The above retrograde orbit solution seems more problem than a direct one."
The comet could reach an elongation that would permit observation by large
telescopes by the end of the month.

2001 CV8 P/LINEAR
A 19th mag object that was reported as asteroidal by LINEAR on February
1.35, and given the designation 2001 CV_8, has
been found by other CCD observers to show cometary activity. M.
Hicks, Jet Propulsion Laboratory, reports that nonphotometric
images (with imperfect tracking) obtained with the 0.61-m f/16
reflector at Table Mountain Observatory by D. Esqueda, A. Esqueda,
and T. H. Ha on Feb. 4 indicate this object to be diffuse without
condensation but with a faint, 5" fan-shaped tail toward the west.
Images taken by D. T. Durig (Sewanee, TN; 0.3-m f/5.8 Schmidt-
Cassegrain telescope; moonlight and tracking problems) on Feb. 6
show the object to be more diffuse than nearby stars. Observations
by J. Ticha and M. Tichy at Klet (0.57-m f/5.2 reflector) on Feb.
10 show the object to be diffuse with a 9" coma and a faint 15"
tail in p.a. 270 deg.
Additional astrometry, orbital elements and
an ephemeris by B. G. Marsden appear on MPEC 2001-C24. The
elements indicate that the comet passed about 0.14 AU from Jupiter
in Nov. 1998 and has a period of 7.8 years with perihelion at 2.12 AU.
[IAUC 7581, 2001 February 10]

2001 E1 SOHO
Michael Oates discovered a faint non Kreutz object on C2 images
on March 15. Studies by Maik Meyer show that it forms a triplet
with 1997 L2 and 2001 X8.
2001 F1 P/NEAT
E. F. Helin, S. Pravdo, and K. Lawrence, Jet Propulsion
Laboratory, report the discovery of a mag 20 comet with a faint tail about
40" long toward the west-northwest on CCD images taken with the
NEAT 1.2-m reflector at Haleakala on March 24.42.
Additional observations, together with orbital elements (T
= 2001 Jan. 21, q = 4.3 AU, i = 19 deg, P = 15.4 yr) by B. G.
Marsden, are given on MPEC 2001-F51. The object appears diffuse on
Mar. 28.5 UT CCD images taken by G. J. Garradd, Loomberah, N.S.W.
(0.45-m f/5.4 reflector). CCD observations by M. Tichy and M.
Kocer at Klet (0.57-m f/5.2 reflector) on Mar. 29.0 show a diffuse
10" coma. P. G. Comba, Prescott, AZ, reports that CCD images taken
with a 0.46-m f/4.5 reflector on Mar. 29.3 show a tail in p.a. 285
deg. [IAUC 7604, 2001 March 29] The comet will fade.
2001 G1 LONEOS
An apparently asteroidal 17th mag object discovered on CCD images taken
with the LONEOS 0.59-m Schmidt telescope on April 1.20 and posted
on the NEO Confirmation Page has been found
by other astrometric observers to be cometary on their CCD images.
The object was reported as being diffuse by J. Ticha, M. Tichy, and
P. Jelinek at Klet (Apr. 1.9 and 2.9 UT; 9" coma on Apr. 2.9) and
by C. E. Lopez and M. R. Cesco at El Leoncito (Apr. 2.2), and as
having a 10" coma by M. Busch and S. Kluegl at Heppenheim, Germany
(Apr. 1.9) and by J. Broughton, Reedy Creek, Queensland (Apr. 2.5).
Additional astrometry and very uncertain parabolic orbital elements
are given on MPEC 2001-G03. [IAUC 7606, 2001 April 2] The comet is
very distant and will fade.

Brain Marsden notes on MPEC 2002-G37 [2002 April 10] that the "original" and
"future" barycentric values of 1/a are +0.000027
and -0.000117 (+/- 0.000009) AU**-1, respectively. This indicates that it is
a new comet from the Oort cloud.

Brain Marsden notes on MPEC 2003-A28 [2003 January 6] that the "original" and
"future" barycentric values of 1/a are
+0.000878
and +0.001234 (+/- 0.000001)
AU**-1, respectively. This indicates that it is not
a new comet from the Oort cloud.

The comet emerged from solar conjunction in the late summer.
Observations in September and October show a small diffuse coma, with the comet around
11th magnitude. By December the comet was clearly fading and was around
13th magnitude in the Northumberland refractor.

2001 J1 NEAT
S. Pravdo, E. Helin, and K. Lawrence, Jet Propulsion
Laboratory, report the discovery of a 17th mag comet by NEAT on CCD images
taken with the 1.2-m reflector at Haleakala on May 11.25. The object appears
diffuse also on confirming CCD observations taken by L. Sarounova
at Ondrejov (coma diameter about 15") and by M. Tichy and J. Ticha
at Klet (coma diameter about 8"-10"). [IAUC 7623, 2001 May 11]

MPEC 2001-J34 contains 40 astrometric observations May 11-15 and
parabolic orbital elements (T = 2001 Mar. 19, q = 1.00 AU, Peri. = 279 deg,
Node = 198 deg, Incl. = 11 deg, equinox 2000.0) computed from 26 of them.
The orbit is still very indeterminate, and it is not clear whether or not
the comet is of short period. [IAUC 7625, 2001 May 15] The comet is
intrinsically very faint.

As hinted on IAUC 7625, this is a short-period comet, and
observations by C. W. Hergenrother, T. B. Spahr, and M. Nelson with
the 1.8-m f/1 VATT Lennon telescope on May 27 make it clear that
the orbital period is $P$ about 7.5-7.9 years. Spahr has also
identified the comet with a very faint object (not described as
cometary) discovered by A. E. Gleason with the Spacewatch telescope
on 2000 Oct. 7 and placed on The NEO Confirmation Page but removed
on Oct. 20 for lack of follow-up. The additional astrometry and
orbital elements ($P$ = 7.64 yr) are given on MPEC 2001-K43. S.
Nakano has noted some rough similarity to the orbit of comet
3D/Biela. [IAUC 7635, 2001 May 29]

Brian Marsden has provided some additional information about this
possibility: While I cannot exclude with 100-percent certainty the
possibility that the new comet P/2001 J1 (NEAT) is the long-lost 3D/Biela,
I really don't think it is.

What, indeed, happened to 3D/Biela after 1852? Did it break up completely?
Some 30 years ago I looked into the possibility of finding that comet again
and published a number of different orbits based on different possibilities
for the action of the nongravitational forces on the comet after 1852. For
an epoch around 1971 these orbits all had perihelion distances under 0.83 AU
and inclinations to the ecliptic under 8.1 degrees.

Coming now to the recent comet, although unusually large inconsistencies
among the observations made it particularly difficult to establish the
orbit, and given that the comet's position in the sky makes it difficult to
observe, I note that some careful observations on May 27 by Carl
Hergenrother and Tim Spahr with the Vatican Advanced Technology Telescope in
Arizona isolated
the revolution period to 7.5-7.9 years. Tim then realized that the object
had in fact been reported as unusual--though not of cometary appearance--by
Arianna Gleason at Spacewatch on October 7 last year. The object was then
listed on The NEO Confirmation Page for almost two weeks, although it was
obviously too faint for essentially all of the likely follow-up observers,
and Spacewatch itself evidently just missed the comet's position when it
recorded the region again on October 19. The October 7 linkage is clearly
correct, and this pins down the current period as 7.64 years.

Running this orbit back gives a moderately close approach to Jupiter (0.8
AU) in 1972, before which the P/2001 J1 perihelion distance was 0.96 AU and
the inclination 11 degrees. While there was tolerably good agreement in
orbital eccentricity, argument of perihelion and nodal longitude, it is
difficult to reconcile the perihelion distance and inclination with the
3D/Biela values. To get these elements to agree would require the
nongravitational forces to act in some special way, together with the
gravitational effects of occasional approaches to Jupiter.

Whether or not the comets are identical, why was the current comet not
observed earlier in the twentieth century? After all, the perihelion
distance of under 1 AU does allow moderately close approaches to the
earth--with a minimum orbital distance of perhaps 0.15 AU and an actual
minimum distance of perhaps 0.5 AU in 1955. Actually, it is quite clear that
at many passages through perihelion the small elongation from the sun would
completely preclude observations, and by the time the object had moved
around to opposition it would be as faint as when Spacewatch fortuitously
observed it last October. Even under the more favorable circumstances of the
1955 perihelion passage, the best one could hope for at a 90-degree
elongation from the sun would be magnitude 15, and more typically (as this
year), one would have to contend with a maximum elongation of 70-80 degrees
and magnitude 16 if one were lucky. We _were_ lucky that NEAT was observing
this year so far from opposition, and there would have been no observing
program with the capability of making the discovery at the previous
comparable elongation in 1985. Unless the comet is now anomalously faint,
that it escaped prior detection is fully reasonable--a situation not a bit
like that of 3D/Biela on several occasions in the late eighteenth and early
nineteenth centuries.

2001 K1 P/NEAT
S. Pravdo, E. Helin and K. Lawrence, Jet Propulsion Laboratory, report
the discovery of a 19th mag comet by NEAT on CCD images taken with the 1.2-m
reflector at Haleakala on May 20.5 and 21.4 UT. M. Tichy and M. Kocer, Klet
Observatory, note that the object had a 14" coma on May 21.9. P. Pravec
and P. Kusnirak, Ondrejov Observatory, report a 0'.3 coma and a 0'.8 tail
in p.a. 290 deg on May 21.9. T. B. Spahr, Minor Planet Center, has identified
asteroidal observations of the object in LONEOS and LINEAR data back to
Feb. 2. Full details are on MPEC 2001-K17. [IAUC 7629, 2001 May 21] The
comet is periodic and will fade.

2001 K5 LINEAR
A 17th mag object reported as asteroidal by the LINEAR program on May
17.28 (with prediscovery LINEAR observations on Apr. 30 identified by
G. V. Williams) and posted on The NEO Confirmation Page has been
found to be slightly diffuse with coma diameter 8" on CCD images
taken at Klet on May 27.0 UT by M. Tichy and J. Ticha and to be
strongly condensed with a 12" coma and a 13" tail in p.a. 210 deg
on 300-s R-band exposures taken with the 1.8-m f/1 Vatican Advanced
Technology Telescope at Mt. Graham on May 27.3 by C. W.
Hergenrother, T. B. Spahr, and M. Nelson. [IAUC 7634, 2001 May 28]
The comet is distant and will remain at around 14th mag visually for some time.
This is LINEARs 64th comet.

2001 M1 P/Helin
M. Busch, A. Seib, F. Hormuth, and R. Stoss, Starkenburg-
Sternwarte, Heppenheim; and A. Gnadig and A. Doppler, Archenhold-
Sternwarte, Berlin, report the recovery of P/1987 Q3 (= 1987w =
1987 XVII) on CCD images taken by Busch, Seib, and Hormuth with the
EOCA 1.52-m reflector at Calar Alto on June 20.14 at 20th magnitude.
The indicated
correction to the prediction by B. G. Marsden on MPC 31664
(ephemeris on MPC 42160) is Delta(T) = -1.0 day. [IAUC 7648, 2001
June 21] The comet will brighten a little.
2001 M10 NEAT
K. J. Lawrence, E. F. Helin, and S. Pravdo, Jet Propulsion
Laboratory, report the discovery by NEAT of a 19th mag
comet on 2001 July 20.28 with the Palomar
1.2-m Schmidt and the Haleakala 1.2-m reflector on June 29.58.
[IAUC 7654, 2001 June 30] The comet is in a distant (q=5.3) orbit with a
period of 138 years.

M. D. Hicks, Jet Propulsion Laboratory, reports that this
comet shows a diffuse coma of diameter about 5" and a faint tail
about 7" long in p.a. 240 deg in a 10-min R-band CCD exposure
obtained on June 30.3 UT with the 0.61-m reflector at Table
Mountain (observers D. Esqueda, Hicks, and T. Ha). Hicks' name
also should be added to the list of NEAT team members on IAUC 7654.
[IAUC 7655, 2001 July 2]

2001 MD7 P/LINEAR
N. Blythe, Lincoln Laboratory Experimental Test System,
reports the discovery by LINEAR of an 17th mag comet on images obtained on
July 11.22, when it appeared diffuse. Subsequent observations
permitted identification with the object 2001 MD_7, so designated
on MPS 31852 as a result of LINEAR observations made on June 21.31 and
24. L. Sarounova reports that CCD images of the comet obtained on
July 12.9 UT at Ondrejov show a bright nucleus and faint coma. [IAUC 7660,
2001 July 12] The comet could reach 13th magnitude in the autumn and it is
possible that it is undergoing an outburst. This is LINEARs 65th comet.

2001 N1 SOHO
Discovered by Xavier Leprette, the orbit for this SOHO comet published on
MPEC 2001-N24 [2001 July 11] is substantially different from the bulk of the
Kreutz group members. Although the comet has a similar perihelion distance
to that of the Kreutz group, the inclination, at 95 degrees, is far from the
usual value of around 144 degrees. This is SOHO's 340th comet.

Further to IAUC 7655, D. Hammer reports measurements of three
additional comets found by M. Oates, X. Leprette, and S. Hoenig on
SOHO website images. All three objects were visible with the C2
coronagraph, and C/2001 O1 was also visible in C3 images. The
reduced astrometry and orbital elements by B. G. Marsden appear on
the MPEC cited below; C/2001 N1 does not seem to be a Kreutz
sungrazer, whereas the other two comets do. [IAUC 7667, 2001 July 19]

2001 N2 LINEAR
An apparently asteroidal 18th mag object reported by LINEAR on
July 11.38, which was posted on the NEO Confirmation Page,
has been found to have a diffuse coma and a faint 5" tail in p.a.
about 90 deg in a 3 min r-band CCD exposure taken with the 0.6-m
reflector at Table Mountain by M. Hicks, D. Esqueda, and T. Ha.
[IAUC 7661, 2001 July 13] The comet reaches perihelion in August 2002
and could reach 13th magnitude.

Regarding the announcement of this comet on IAUC 7673, the
observations on July 25 were made at Haleakala, while those on July
29 were made at Palomar. Additional astrometry and
very uncertain parabolic orbital elements (from 17 observations,
July 25-Aug. 1) and an ephemeris appear on MPEC 2001-P01. [IAUC 7676,
2001 August 1]. The comet is a distant one, past perihelion and will fade.

2001 OG108 LONEOS
Asteroid 2001 OG108, discovered by LONEOS on July 28.39 at 19th magnitude, has
a high inclination cometary type orbit, though no activity has so far been
detected. With a period of 51 years it doesn't reach its perihelion of 1AU
until March 2002, when it may reach 14th magnitude at high northern
declination. If it does show any cometary activity it may well be brighter
than this. Details of the observations and orbit were given on MPEC 2001-P40
on August 13.

As the clue of a cometary type orbit suggested, this object did eventually
show cometary activity and is brightening rapidly. I observed it on February
9.81 and estimated it at 11.3: in the Thorrowgood refractor. On March 28.84 I
was able to see it in the same instrument, despite strong moonlight and
observing through trees, estimating it at 10.2. The comet is now fading and
is quite a diffuse object making it difficult to locate.

Large Earth-Crossing Asteroid Found
A newly discovered rare asteroid may be the largest Earth-crosser known.

by Vanessa Thomas

During the past decade, astronomers have begun finding members of an unusual
breed of asteroids. Called Damocloids after the first of their kind
discovered, 5335 Damocles, these asteroids have elliptical orbits that
resemble those of short-period comets like Comet Halley. A new member of
this strange astronomical club has now been found, and its brightness
suggests that it might be the largest Earth-crossing asteroid known.

Provisionally titled 2001 OG108, the object was first spotted on July 28 by
Michael Van Ness, an observer for the Lowell Observatory Near-Earth-Object
Search (LONEOS) program in Arizona. Over the next two weeks, observers
tracked the newfound asteroid to determine its path about the sun. Like
other Damocloids, 2001 OG108 has an elongated orbit. Each trip about the sun
takes it from beyond Uranus to just within Earth's orbital path.

Because Damocloids mimic the course of short-period comets, astronomers
suspect these unique asteroids might actually be "dead" comets. While the
gas and ices that cause comets to flare up when they approach the sun may
have been exhausted, the dark, rocky remains continue to travel through the
solar system. If this notion is correct, these asteroids should have the
same dark surfaces typical of short-period comet nuclei.

However, 2001 OG108 is one of the brightest Earth-crossing asteroids found
so far. According to LONEOS director Ted Bowell, just two other
Earth-crossers rival it in brightness. But 1866 Sisyphus and 2000 WF129
orbit the sun in the inner solar system and are unlikely to be as
intrinsically dark as 2001 OG108, Bowell says. If the newly discovered
asteroid is darker and reflects less light than Sisyphus and 2000 WF129, but
appears just as bright, it must be larger.

Based on its brightness, its current distance, and an expectation of its
albedo, Bowell estimates that 2001 OG108 could be as large as 10 miles (15
kilometers). The median size of the approximately 800 known Earth-crossing
asteroids is less than one kilometer, so "this object really sticks out," he
says.

Although 2001 OG108 will occasionally zip past Earth during its 50-year
journey about the sun, Bowell assures that Earthlings need not worry that
the asteroid will impact Earth - at least not in the near future. In its
present orbit, the Damocloid will not come any closer to us than about 28
million miles (about 45 million kilometers), or more than 100 times the
distance between Earth and its moon. The astronomer points out, however,
that the asteroid could potentially pass within 100 million miles of
Jupiter, which may result in an orbital adjustment by the giant planet's
gravitational manipulation.

Currently passing through the main asteroid belt toward the inner solar
system, 2001 OG108 will make its next close approach to Earth in April of
next year. As it zooms past Polaris in our northern skies, the asteroid will
be bright enough for amateur astronomers to spot with moderately sized
telescopes. Professional astronomers will likely take interest in this rare
space rock as well, in order to study its composition and attempt to confirm
its once-cometary nature.

46 visual observations give a preliminary uncorrected light curve of
10.2 + 5 log d + 5.9 log r, although this is a poor fit.
This suggests that
the comet should have been visible to visual observers long before February.

2001 P1 SOHO
Discovered by Tony Scarmato, the orbit for this SOHO comet published on
MPEC 2001-P22 [2001 August 8] is substantially different from the bulk of the
Kreutz group members. Although the comet has a similar perihelion distance
to that of the Kreutz group, the inclination, at 151 degrees, is far from the
usual value of around 144 degrees and the value of L is around 208.
This is SOHO's 343rd comet.
2001 P2 SOHO
Discovered by Sebastian Hoenig, the orbit for this SOHO comet published on
MPEC 2001-Q02 [2001 August 16] is substantially different from the bulk of the
Kreutz group members. Although the comet has a similar perihelion distance
to that of the Kreutz group, the inclination, at 130 degrees, is far from the
usual value of around 144 degrees and the value of L is around 220 degrees.
This is SOHO's 344th comet.
2001 P3 39P/Oterma
Y. R. Fernandez, University of Hawaii, reports his recovery of
comet 39P on CCD frames obtained on Aug. 13.42 at 22nd mag with the
2.2-m University of Hawaii reflector, confirmatory images being
obtained on Aug. 20 and 21 by K. J. Meech and J. Pittichova. The
object, a point source, was located about 2' from the prediction by
B. G. Marsden on MPC 34423 (ephemeris on MPC 42373). Meech then
succeeded in locating the comet on her CCD frames from 1999 May 9
and July 15. M. A. Kadooka and J. M. Bauer assisted, and the
measurements by Meech are given on MPEC 2001-Q35. The recovery
also confirms the correctness of positions tentatively measured by
G. V. Williams from images obtained by D. C. Jewitt, J. X. Luu, and
C. A. Trujillo on 1998 May 1 and 22. MPEC 2001-Q35 also includes
orbital elements from 227 observations (1942-2001) and a revised
ephemeris. Last observed in Aug. 1962, comet 39P passed 0.095 AU
from Jupiter on 1963 Apr. 12, after which q increased from 3.4 to
5.5 AU and P from 7.9 to 19 years (with T = 1983 June 18 and 2002
Dec. 22). [IAUC 7689, 2001 August 24]
A/2001 PT13
This is a distant asteroid, with perihelion at 8.5 AU in 1999 February, with
a period of 35 years.
2001 Q1 NEAT
K. J. Lawrence, E. F. Helin, and S. Pravdo, Jet Propulsion
Laboratory, report the discovery by the Near Earth Asteroid
Tracking program of a new 19th mag comet on CCD images obtained with the
1.2-m Oschin Schmidt telescope at Palomar on August 17.20

Lawrence notes that the object is diffuse with a nuclear
condensation of diameter about 3". Following posting on the NEO
Confirmation Page, P. Pravec and P. Kusnirak (Ondrejov 0.65-m
reflector) confirmed its cometary appearance on CCD images obtained
on Aug. 18.9 UT, and M. Kocer (Klet 0.57-m reflector) reports that
the object is diffuse and at m_1 = 18.0 on Aug. 18.9. T. B. Spahr,
Minor Planet Center, has also identified the object in data
obtained by LONEOS on July 16.2. Full astrometry and
parabolic orbital elements appear on MPEC 2001-Q18. [IAUC 7685,
2001 August 18]. The comet is distant and will not get any brighter.

2001 Q2 P/Petriew
Vance Avery Petriew, Regina, SK, reports his visual discovery
of an 11th mag comet during a star party at Cypress Hills Interprovincial Park, Saskatchewan on
August 18.42. The object's presence was also confirmed visually by
R. Huziak (0.25-m reflector) and P. Campbell (0.32-m reflector) at
Cyprus Hills.

Additional astrometry and orbital elements by
B. G. Marsden, Smithsonian Astrophysical Observatory, appear on
MPEC 2001-Q31. The eccentricity is very uncertain, and the orbit
indicates a close approach to Jupiter in 1982. S. Nakano, Sumoto,
Japan, has also computed an elliptical orbit and notes the
similarity to the orbit of comet 103P. [IAUC 7688, 2001 August 21]
The ephemeris suggests that the comet should have been within visual
range since July, which suggests that either the comet has recently outburst
(or has a steep light curve)
or that the morning sky is not being well patrolled by amateur comet hunters.

From the SPA ENB 2001 August 27

In centuries past astronomers discovered new comets the old-fashioned way:
they peered through telescopes or simply looked toward the sky, hunting
for faint smudges that no one had seen before. It was hard work, but lots
of people did it. Comets are named after their discoverers, after all, and
finding a new one can mean instant fame. Hale-Bopp, Hyakutake and
Shoemaker-Levy are just a few of the names we know ... because of comets.

But lately it seems just about every new comet is called "LINEAR" or
"NEAT." Those are names, too, but not the names of humans. They're
robots -- automated, computer controlled telescopes that scan the skies in
a relentless search for near-Earth asteroids and comets. This year between
January and mid-August such telescopes recorded 18 new comets, while
humans had found none. Comet hunters -- the human kind -- just can't
compete! At least that's how many beleaguered sky watchers have been
feeling. But now Canadian amateur astronomer Vance Petriew has proved
humans can still discover a comet the old-fashioned way.

Petriew was at the Saskatchewan Summer Star Party on August 18th when he
turned his 20" telescope toward the Crab Nebula. Hopping from one star to
another across the constellation Taurus, Petriew guided his telescope
toward the famous supernova remnant -- but he never made it. He stopped
instead at a curious smudge that appeared unexpectedly in his eyepiece.
Thinking it might be a galaxy, he looked at his star charts to see if any
were nearby, but there was no galaxy in the vicinity.

Petriew announced his comet discovery hours later, and since then
astronomers have been monitoring the newfound comet to learn more about
it. Based on data spanning less that a week, it appears that Comet Petriew
may be travelling around the Sun once every 5.5 years following an
elliptical path that stretches from a point just inside Earth's orbit
(0.95 AU) out to the realm of the giant planet Jupiter (5.3 AU).

Says Brian Marsden of the Smithsonian Institution's Minor Planet Center:
"We're still not completely sure of the orbital period, but Comet Petriew
might have passed close to Jupiter in 1982 -- an encounter that could have
nudged the comet into its current orbit." Before 1982 Comet Petriew's
orbit was probably bigger than it is now. It couldn't have come so close
to Earth in decades past, which might explain why it was never spotted
before.

The comet should reach around magnitude 10.5 and then slowly fade as it
recedes from our planet, as well as from the Sun. If the comet is
well-behaved, it should remain brighter than 11th magnitude through
mid-September. If it behaves like comet 103P, which continued brightening
for nearly two months after perihelion, it could brighten to 8th magnitude
in October.

The comet is a relatively easy object in the morning sky. Observing on August 27.12
with 20cm T x75 I made it 10.1, DC3 and 1.6' diameter, and in 14x100B it was 9.3, DC3
and 4.7' diameter. An observation in mid September suggested that it had
changed little in brightness, however it is now fading and is likely to be fainter
than 13th magnitude by the end of October.

2001 Q3 SOHO
This non Kreutz comet, discovered by Chen Hua Dong on SOHO imagery on August 25, may
be observable from the ground. An ephemeris is given on MPEC 2001-Q60, though
it will be very faint by the time it reaches a reasonable solar elongation.

Further to IAUC 7689, D. Hammer reports astrometric
measurements of a comet found by Chen Dong Hua on SOHO website
images. The object was first detected on August 25.34 at mag 8.3
in LASCO C2 coronagraph images, moving southward from
directly underneath the occulter; the comet brightened and showed a
nice tail before entering the C3 field-of-view, where it began to
fade, as indicated by the following additional V magnitudes
provided by D. Biesecker and Hammer: Aug. 25.393 UT, 7.6; 25.463,
7.4; 25.977, 5.7; 26.102, 4.8; 26.221, 5.2; 26.227, 4.6; 26.446,
5.8; 26.811, 8.0. [IAUC 7694, 2001 August 28]

C. E. Woodward, University of Minnesota; D. H. Wooden, NASA
Ames Research Center; and D. E. Harker, University of San Diego,
report 8-13-micron spectrophotometry of this comet on May 11.2 UT
using the NASA Ames HIFOGS spectrometer at the Infrared Telescope
Facility 3-m reflector: "Silicate-feature emission was observed
with a flux-to-continuum ratio of 1.6, including emission from
crystalline silicates at 9.3, 10.0, and 11.2 microns. The 10-
micron peak flux was 1.6 x 10**-16 W cm**-2 micron**-1, and the
observed N-band magnitude was -0.22 +/- 0.07. A blackbody fit to
the local continuum yields a color temperature of 310 +/- 4 K."
[IAUC 8339, 2004 May 13]

J. L. Wilde and M. L. Sitko, University of Cincinnati; and D.
L. Kim and R. W. Russell, The Aerospace Corporation, report 3-13-
micron spectrophotometry of comet C/2001 Q4 obtained on May 14.1 UT
with the Mt. Lemmon 1.5-m University of Minnesota telescope (+
Aerospace Broadband Array Spectrograph System; 8".5 aperture; 51"
chop throw; integration times 20 min on the comet and 10 min on the
reference star, beta Gem): "A smooth comet continuum was seen to
rise from 3 to 5 microns and from 7.1 to 8.4 microns, a little
above the blackbody (about 310 +/- 5 K) that was fit to the
continuum points on either side of the strong, structured silicate
feature seen from 8.4 to 12 microns. This temperature is
consistent with the temperature reported by Woodward et al. (IAUC
8339) but is dependent upon assumptions of where the silicate grain
emissivity becomes much less than the emissivity of the (assumed)
gray-body grains that emit the underlying contiuum. The grain
temperature is about 9 percent higher than that of an equilibrium
blackbody at the heliocentric distance of the comet. The continuum
was fairly flat beyond 12 microns. The rising flux above the
blackbody from 7 microns towards 3 microns may be due to scattered
sunlight, thermal emission from grains with a mix of temperatures
and optical properties, or both. Structure is seen in the silicate
feature, but at slightly different wavelengths from those reported
by Woodward et al. Here, emission peaks are seen at 10.5 and 11.2
microns, with no feature at 9.3 microns. The silicate-feature-to-
continuum ratio was about 1.65, also consistent with the report by
Woodward et al. With our aperture, the comet has narrowband (about
0.25 micron) magnitudes and combined random errors (due to
calibration star and comet) of [3.5 microns] = 5.44 +/- 0.09, [4.5
microns] = 3.44 +/- 0.03, [5 microns] = 2.96 +/- 0.03, [8 microns]
= -0.10 +/- 0.01, [10.5 microns] = -1.65 +/- 0.01, and [12 microns]
= -1.72 +/- 0.03. The combined comet-and-calibration-star
systematic intensity uncertainty is estimated at about 5 percent.
The ratio of this brightness to that of Woodward et al. is
consistent with a roughly linear dependence on aperture, or a 1/R
radial grain-density dependence from the comet nucleus."
[IAUC 8342, 2004 May 19]

J. Lecacheux, LESIA, Meudon Observatory; and E. Frappa,
St-Etienne Planetarium, write: "We have observed the concentric
dust shells of comet C/2001 Q4 with the Pic-du-Midi 1.05-m
reflector during six 3-hr sessions from May 14 to 19, around the
time of perihelion. Direct measurement of the radial expansion on
consecutive exposures yields 163 +/- 20 m/s. From the measured
12000-km shell interval, a first approximation of P = 20.5 +/- 3 hr
can be inferred for the period of nucleus rotation, suggesting the
exclusion of any value shorter than 17-18 hr. Then by blinking
images of the inner shell taken at 1-day or several-day interval(s),
and assuming constant expansion velocity, we obtain a refined
probable period P = 23.2 +/- 0.25 hr. We also followed a small
dust jet rotating counterclockwise (facing the sun) on May 14; its
estimated angular motion of about 16 deg/hr agreed with the above
period. Fibrous-like features, not more 300 km wide, appear within
the brightest shell at 10000-15000 km from the nucleus; they show a
pure radial expansion and no other morphology change in 3 hr, and
they recur in the following shell 0.9 day later. In fact, we
observe a complex of 3 or or 4 muddled components (sub-shells),
issued from so many active regions and with slightly different
expansion rates."
[IAUC 8349, 2004 May 31]

S. M. Brafford, University of Dayton; M. L. Sitko, University
of Cincinnati; and R. W. Russell and D. L. Kim, The Aerospace
Corporation, report 3-13-micron spectrophotometry of comet C/2001
Q4, obtained on May 31.2 UT with the Mt. Lemmon 1.5-m University of
Minnesota telescope (+ Aerospace Broadband Array Spectrograph
System; 8".5 aperture; 49" chop throw; integration times 10 min on
the comet and 20 min on the reference star, alpha Lyr): "A smooth
comet continuum was seen to rise from 3.5 to 8.4 microns, beyond
which a strong silicate emission band was observed. An underlying
blackbody continuum with a temperature of about 345 +/- 10 K was
fit to the continuum flux at 5, 8.4, and 12 microns. This grain
temperature is about 24 percent higher than that of an equilibrium
blackbody at the heliocentric distance of the comet, and higher
than that observed on May 14.1 (IAUC 8342) using the same
instrument and telescope when the comet was closer to the sun.
Structure is seen in the silicate feature, including emission peaks
at 10.5 and 11.2 microns. The silicate-feature-to-continuum ratio
was about 1.43 +/- 0.04, lower than that reported on May 14.2. No
scattered solar flux was detected at the shorter wavelengths after
subtracting the thermal continuum. With our aperture, the comet
has the following narrowband (about 0.25 micron) magnitudes and
combined random errors (due to calibration star and comet, as well
as variations due to the presence of real spectral structure):
[3.7 microns] = 6.8 +/- 0.3, [4.7 microns] = 4.60 +/- 0.11, [5
microns] = 4.27 +/- 0.06, [8 microns] = 1.71 +/- 0.06, [10.5
microns] = -0.54 +/- 0.02, and [12 microns] = -0.49 +/- 0.03 (the
stated errors are standard deviations of the mean)."
[IAUC 8351, 2004 June 11]

Further to IAUC 8351, W. J. Carpenter (University of
Cincinnati), M. L. Sitko, R. W. Russell, and D. L. Kim report
additional 3-13-micron spectrophotometry of C/2001 Q4, obtained on
June 17.2 UT at Mt. Lemmon (integration time 45 min; reference star
alpha Boo): "A smooth comet continuum was seen to rise from 3.5 to
8.4 microns, beyond which a moderate silicate emission band was
observed. An underlying blackbody continuum with a temperature of
about 305 +/- 5 K was fit to the continuum flux at 5, 8.4, and 12
microns. This grain temperature is about 16 +/- 2 percent higher
than that of an equilibrium blackbody at the heliocentric distance
of the comet. The silicate-feature-to-continuum ratio was about
1.26 +/- 0.02 -- lower than the values of 1.65 reported on May 14.2
(IAUC 8342) and 1.43 reported for May 31.2 (IAUC 8351). During the
period of observation, the strength of the silicate feature above
the continuum was unchanged. The crystalline olivine feature at
11.2 microns continues to be present with approximately the same
contrast as orginally seen. With our aperture, the comet has the
following narrowband (about 0.25 micron) magnitudes and combined
random errors: [3.7 microns] = 7.75 +0.45/-0.33, [4.7 microns] =
5.68 +0.20/-0.17, [5 microns] = 5.61 +0.23/-0.18, [8 microns] =
1.96 +/- 0.10, [10.5 microns] = 0.43 +/- 0.03, [12 microns] = 0.15
+/- 0.02."
[IAUC 8358, 2004 June 18]

Further to IAUC 8358, R. W. Russell, D. L. Kim, M. L. Sitko,
and W. J. Carpenter, report additional 3-13-micron
spectrophotometry of C/2001 Q4, obtained on June 20.2 UT at Mt.
Lemmon (integration time 45 min; reference star alpha Boo): "A
smooth comet continuum was seen to rise from 3.5 to 8.4 microns,
beyond which a moderate silicate emission band was observed. An
underlying blackbody continuum with a temperature of about 315 +/-
5 K was fit to the continuum flux at 5, 8.4, and 12 microns. This
grain temperature is about 21 +/- 2 percent higher than that of an
equilibrium blackbody at the heliocentric distance of the comet.
The silicate-feature-to-continuum ratio was 1.32 +/- 0.02 --
slightly greater than the value of 1.26 reported on June 17.2 (IAUC
8358), but still significantly less than that reported on May 31.2
(1.43; IAUC 8351) and May 14.2 (1.65; IAUC 8342). The crystalline
olivine feature at 11.2 microns continues to be present with
approximately the same contrast as originally seen. With our
aperture, the comet has the following narrowband (about 0.25 micron)
magnitudes and combined random errors: [3.7 microns] = 7.73 +/-
0.17, [4.7 microns] = 5.49 +/- 0.20, [5 microns] = 4.95 +/- 0.23,
[8 microns] = 2.10 +/- 0.18, [10.5 microns] = 0.50 +/- 0.05, [12
microns] = 0.26 +/- 0.04."
[IAUC 8360, 2004 June 23]

The "original" value of 1/a
suggests that this is a new visitor from the Oort cloud.

Observations in early September 2003 put the comet at around 12th magnitude.
Alexandre Amorim, observing on September 20.31 with a 0.14-m reflector x80
estimated the comet at 12.3 with a 0.5' coma. Observing with 20x80B in mid January
Alexandre made the comet 8.9. By early February he was reporting it at 8th
magnitude. I observed the comet from Stanley, Falkland Islands on February 19.03,
where it was 40 degrees altitude and estimated it at 7.2 with a 9' coma. I flew to
Rothera in the Antarctic the next day. On February 26.14 I was able to observe it in
rather bright skies (sun 12 degrees below the horizon) and with a little cloud
interference estimated it at 7.3 in 10x50B. On March 5.12 I had another view and made
it a fraction brighter at 7.2. We then had a lengthy spell of cloudy weather, but with a
forecast of clearing skies I arranged for an early morning call and made another observation on
March 16.28. The comet was significantly brighter and I made it 6.9, with a 10' diameter coma.
I left Rothera on March 19 and was able to make a couple more observations
on the voyage to the Falkland Islands. We berthed at FIPASS just outside
Stanley and from there is a short walk over a hill to dark skies. From
here on March 25.00 I estimated the comet at 6.6 in 10x50B, with a 9' coma
and 40' tail, and was also able to glimpse it with the naked eye at 6.0.

I observed the comet from the UK on May 10.8 and found it somewhat disappointing
under rather hazy skies. In 20x80B it was 4.0, with a 15' DC5 coma and hints
of a 0.8 degree long tail. Between May 16 and 23 I was staying at Hohenpeissenberg in
the Bavarian alps and was able to observe the comet on several occasions. My first
observation on May 16.8 put it at 3.5 in 10x25 binoculars, with a 2.7 degree long tail.
By May 20.8 it had faded to 4.4, with a 1.5 degree long tail. It continues to fade very
slowly, and by June 12.9 was 6.1, though still with a faint 0.5 degree tail. By mid
August it had faded to 8.5, but was still an easy binocular object. By mid September
it required a telescope, and I estimated it at 10.2 on September 18.92 in a 30cm reflector,
however other observers were estimating it a little fainter.

Michael Mattiazzo gives the dates of the orbital plane crossings as 2003 April
21, 2003 Oct 24, 2004 April 20 and 2004 October 23.

1044 observations give a preliminary uncorrected light curve of
5.7 + 5 log d + 6.6 log r though it is currently about 1.5 magnitudes
fainter than indicated by the mean curve.

2001 Q7 SOHO
A non Kreutz object of 8th magnitude discovered by R Kracht on C2 images on August 21.
2001 Q11 (P/NEAT)
Maik Meyer, Limburg, Germany, has discovered a 19th magnitude comet on images obtained by the NEAT project on three nights at
Palomar and on five nights at Haleakala during August - December 2001. The August 18.47 Palomar discovery-night
images show a 21" tail in p.a. 256 deg, and there was a 0'.2 tail in p.a. 264 deg on the August 22 Haleakala
frames. The August 18 observations were reported (though not as being cometary) by NEAT at the time
(mag 18.6-18.7), but the object was never followed up; likewise for four LONEOS observations (mag 17.9) on October 24.
The comet was at perihelion in 2001 June and has a period of around 6.2 years.
Searches of relevant frames by Meyer and others have so far failed to show the comet at its return in 2007.
[IAUC 9129, 2010 March 19]
A/2001 QF6 (LINEAR)
Discovered by LINEAR on August 16.27, this 19th mag asteroid has a 19 year
period, with perihelion at 2.2 AU. It reached perihelion in February 2002,
but no cometary activity was seen. It can pass within 0.3 AU of Jupiter, but
has not done so recently.
A/2001 QL169 (NEAT)
Discovered by NEAT on August 17.47, this 20th mag asteroid has a 5.5 year
period, with perihelion at 1.53 AU and is just past perihelion. The orbit is
typical of a short period comet and makes close approaches to Jupiter. The
orbit is not significantly changed by approaches in 1860 (0.74 AU), 1943
(0.74 AU), 2014 (0.78 AU) and 2098 (0.84 AU). [MPEC 2001-R05, 2001 September
1]
2001 R1 P/LONEOS
An apparently asteroidal 18th mag (red) object discovered by LONEOS on September 10.19 and
posted on the NEO Confirmation Page has been found cometary. It has a period of 7.89
years and will be at perihelion on 2002 January 30. [IAUC 7713, 2001 September 11]
It will brighten a little, but will not come within visual range.

Improved orbital elements were published on MPEC 2001-S05, including
prediscovery observations on Aug. 19 by LINEAR by B. G. Marsden and these
indicate that
this comet will pass only 0.014 AU from Mars on 2002 Jan. 10.7 TT,
as first suggested by C.-I. Lagerkvist (Uppsala) and G. Hahn
(German Aerospace Center, Berlin). [IAUC 7720, 2001 September 19]

2001 R6 P/LINEAR-Skiff
B. A. Skiff, Lowell Observatory, reports his discovery of a
17th mag comet on CCD images taken by him with the LONEOS telescope on Sept.
25.32. The object shows a moderately condensed 15" coma and a broad
tail about 25" toward the west-northwest. T. B. Spahr identified
this comet with an object observed on two nights (Sept. 11 and 16,
previously linked; m_2 = 19.4-20.0) and reported as asteroidal in
appearance by LINEAR; subsequently LINEAR observations from Aug. 19
were also identified. J. G. Ries reports that CCD images obtained
with the 0.76-m reflector at McDonald Observatory on Sept. 27.3 UT
also show this object to be diffuse. [IAUC 7723, 2001 September 27]
The comet has a period of 8.3 years and a perihelion distance of 2.1 AU.

2001 RX14 LINEAR
The linkage by the Minor Planet Center of subsequent
observations of an apparent 19th mag main-belt minor planet observed by
LINEAR on Sept. 10.32 and 11 showed that this object, designated 2001
RX_14 on MPS 34978, had a nearly parabolic orbit. After placement
on the NEO Confirmation Page, many further observations were
received, with M. Tichy (Klet, 0.57-m f/5.2 reflector + CCD) on
Oct. 18.7 UT indicating that the comet appeared to be diffuse with
a coma of diameter 13" and red mag 16.7. R-band images taken by C.
Hergenrother and J. Barnes (Lunar and Planetary Laboratory) with
the 1.54-m Catalina reflector on Oct. 24.32 show a highly condensed
coma of diameter 6" and no hint of a tail. [IAUC 7739, 2001 October 26]

Brian Marsden notes on MPEC 2002-S05 that the "original" and "future"
barycentric values of 1/a are
+0.000776 and +0.000257 (+/- 0.000003) AU**-1, respectively.
[2002 September 16] The "original value of 1/a
suggests that this is not a new visitor from the Oort cloud.

The comet reached perihelion at 2.06 AU in January 2003 and reached
10th mag. Visual observers reported it at around 13th magnitude in early
September 2002. It had brightened to around 12th magnitude by early November
according to reports from Carlos Labordena and Jonathan Shanklin.
Observations in January 2003 give magnitudes between 10 and 11.

2001 RG100 158P/Kowal-LINEAR
An asteroid discovered by LINEAR on 2001 September 12.26 was found
to be a comet on CCD images taken with the Spacewatch 0.9-m reflector
on 2003 November 26.4. The comet was at perihelion in late July 2002
and has a 10.3 year period with perihelion at 4.6 AU. It was put into
its present orbit following an encounter to within 0.25 AU of Jupiter in
1943, prior to which perihelion was at 7.0 AU. In 2022 another encounter
to 0.75 AU will pull the perihelion out to 5.7 AU.

S Nakano has identified the comet with 1979 O1, observed by Charles Kowal
on three occasions between July 24 and 27 and then lost. The orbit was
uncertain, but noted as possibly being periodic due to the low inclination.

CCD exposures taken by A. E. Gleason with the 0.9-m f/3
Spacewatch reflector at Kitt Peak on Nov. 26.4 UT show that the
object 2001 RG_100 (discovered by LINEAR on 2001 September 12.26)
is definitely a comet, showing a nuclear condensation
of diameter approximately 6" and a tail 18" long in p.a. 265 deg.
Following a request from the Minor Planet Center, J. Young reports
that CCD images taken at Table Mountain on Nov. 27 show a 4" coma
with a broad, faint tail extending approximately 12" in p.a. 265
deg.
[IAUC 8244, 2003 November 28]

Further to IAUC 8244, S. Nakano (Sumoto, Japan) reports that
comet P/2001 RG100 (LINEAR) is identical with C/1979 O1 = 1979h
(Kowal; cf. IAUC 3395 and 3397; MPC 4904 and 4998), suspected at
the time as being of short period but lost immediately after
discovery. Nakano's improved orbital elements, given on Nakano
Note 995, are very similar to those for the 2002 and 1992 epochs on
MPEC 2003-W74, and he also gives elements for a 1981 epoch (T =
1981 Sept. 14).
[IAUC 8247, 2003 December 2]

2001 S1 Skiff
B. Skiff, Lowell Observatory, reports his discovery of an
apparent 20th mag comet on LONEOS telescope images obtained on Sept. 26.4
UT, when the object appeared distinctly less well concentrated than
nearby stars (despite poor seeing), with an apparent 17" coma.
Observations by R. H. McNaught at Siding Spring on Sept. 26 show a
coma barely different from the 2"-3" seeing but with a short tail
(< 10" long) in p.a. about 40 deg. J. G. Ries reports that CCD
images obtained with the 0.76-m reflector at McDonald Observatory
on Sept. 28.4 confirm the northeastward tail of length about 10".
[IAUC 7725, 2001 September 29] The comet is distant and past perihelion
and will fade.
A/2001 SS107 (LINEAR)
An asteroid discovered by LINEAR on September 20 has a perihelion
distance of 1.51 AU and a period of 5.46 years in a typical Jupiter familly comet
orbit. Perihelion was on 2002 March 9.4.
A/2001 SS287 (LINEAR)
A 19th mag asteroid discovered by LINEAR on September 27.41 has a perihelion
distance of 1.07 AU and a period of 6.13 years in a typical Jupiter familly comet
orbit. Perihelion was on October 20.75.

Following recovery in 2007 the orbit was refined to give perihelion distance at
1.06 AU on 2007 September 1.7 and a period of 5.85 years. It can pass 0.07 AU
from the Earth and 0.1 AU from Jupiter.

2001 T1 SOHO
A non Kreutz object discovered by Xavier Leprette on C2 images on October 9.
2001 T3 P/NEAT
K. Lawrence, S. Pravdo, and E. F. Helin, Jet Propulsion
Laboratory, report the discovery on October 14.45 by the NEAT program of an
18th mag comet
with a faint coma on CCD images taken with the Palomar 1.2-m
Schmidt telescope. The object also appears cometary on CCD images
taken by P. Pravec and P. Kusnirak at Ondrejov (moderately
condensed coma of diameter 0'.2 on Oct. 14.9 UT) and by J. Ticha,
M. Tichy, and P. Jelinek at Klet (diffuse 11" coma on Oct. 14.9;
10" coma and m_1 = 17.0 on Oct. 15.8). [IAUC 7733, 2001 October 15]
The comet is in a 16 year periodic orbit with perihelion at 2.5 AU. It
will fade.
2001 T4 P/NEAT
S. Pravdo, E. F. Helin, M. Hicks, and K. Lawrence, Jet
Propulsion Laboratory, report the discovery by the NEAT program of
a 20th mag comet with a diffuse coma of diameter about 4" and a southward
tail about 10" long on CCD images taken on Oct. 15.35 with the Palomar
1.2-m Schmidt telescope. Additional NEAT images on Oct. 21.4 UT
show the comet as very diffuse and faint, elongated east-west.
The comet has a perihelion distance of 8.6 AU and a period of 52 years.
[IAUC 7738, 2001 October 23]
2001 T5 SOHO
A non Kreutz comet discovered by XingMing Zhou on October 17 in C3 images from
October 14.
[IAUC 7750, 2001 November 10]
2001 TD45 (LINEAR)
A/2001 TD45 (LINEAR) is another faint asteroid of 20th magnitude, discovered
by LINEAR on October 15.40. It's 0.72 year orbit takes it to within 0.17 AU
of the Sun at perihelion and out to the orbit of Mars at aphelion.
2001 TU80 LINEAR-NEAT
An 18th mag object independently discovered and reported as nebulous
with a 3" coma by NEAT at Palomar on Nov. 16.53 UT has been
identified by G. V. Williams, Minor Planet Center, with an
apparently asteroidal object reported on Oct. 13.44 and 17 by LINEAR
(m_2 = 19.8; discovery observations on MPS 39482) and on Oct. 19 by
NEAT at Haleakala (MPS 40840), from which an apparently routine
minor-planet orbit was computed (MPEC 2001-V35). Following posting
on the NEO Confirmation Page, P. Kusnirak at Ondrejov found the
comet to be moderately condensed with a 0'.3 coma on CCD images
taken on Nov. 17.2 with a 0.65-m f/3.6 reflector. [IAUC 7753, 2001 November 17]
The comet is in a short period orbit of 7.2 years, with perihelion of 1.94 AU in mid
December and will fade.

The comet passed within about 0.1 AU of Jupiter in 1985, prior to which it was
in a more distant, less eccentric orbit.

A/2001 TX16 (LINEAR)
A/2001 TX16 (LINEAR) is an asteroid, of 17th magnitude, discovered by LINEAR
on October 13. With a period of 6.77 years, the orbit is typical of a
Jupiter family comet. There were approaches to Jupiter of 0.80 AU in 1985
and 0.73 AU in 1937. No observer has reported this object to have cometary
appearance. [MPEC 2001-U45, 2001 October 25] It reaches perihelion at
1.44 AU in January, so may yet show cometary activity.
2001 U6 LINEAR
An apparently asteroidal object of 19th mag discovered on Oct. 29.40 by
LINEAR, posted on the NEO Confirmation Page due to its unusual
motion, has been found to be cometary by J. Ticha and M. Tichy
(Klet, diffuse with "a slight coma" on Nov. 3.8 UT) and by R.
Trentman (Louisburg, KS, Nov. 6.3). [IAUC 7746, 2001 November 6] The
comet is distant and will reach perihelion in August 2002. It will not
come within visual range.

Brian Marsden notes on MPEC 2002-S07 that the "original" and "future"
barycentric values of 1/a are
+0.000998 and +0.001075 (+/- 0.000004) AU**-1
respectively. [2002 September 16] The "original value of 1/a
suggests that this is not a new visitor from the Oort cloud.

A/2001 UO16 (LINEAR)
A/2001 UO16 (LINEAR) is an asteroid, of 19th magnitude, discovered by LINEAR
on October 21.26. With a period of 6.13 years, the orbit is typical of a
Jupiter family comet. It was at perihelion at the beginning of October.
[MPEC 2001-U51]
A/2001 UU92 (NEAT)
A/2001 UU92 (NEAT) is an asteroid, of 19th magnitude, discovered by NEAT
on October 19.32. With a period of 5.63 years, the orbit is typical of a
Jupiter family comet. It will be at perihelion at 1.05 AU at the end of December.
[MPEC 2001-W34]
A/2001 VJ75 (LINEAR)
A/2001 VJ75 (LINEAR) is an asteroid, of 20th magnitude, discovered by LINEAR
on November 12.45. With a period of 5.20 years, the orbit is typical of a
Jupiter family comet. It was at perihelion at 1.07 AU at the beginning of
November. [MPEC 2001-W05]
2001 W1 LINEAR
A 19th mag object reported by LINEAR as apparently asteroidal but with
unusual motion on November 17.43, and thus posted on
the NEO Confirmation Page, has been found to appear cometary by
other observers. CCD images taken by J. Nomen (Barcelona, Spain,
0.40-m f/2 Schmidt telescope) on Nov. 18.15 UT show the object to
be slightly diffuse (m_1 = 18.0). CCD observations obtained by T.
Spahr at the 1.2-m Mount Hopkins reflector on Nov. 18.33 show a
very diffuse coma of diameter about 7" and a very faint tail about
15" long in p.a. 200 deg. [IAUC 7754, 2001 November 19].
The comet will brighten a little.
2001 W2 BATTERS
S. Nakano, Sumoto, Japan, reports the discovery of a 14th mag
comet on November 21.45
by A. Asami on CCD images taken with the Bisei Spaceguard Center
0.50-m f/2.0 reflector in the course of the "Bisei Asteroid
Tracking Telescope for Rapid Survey" program. Additional
observations were reported following posting on the NEO
Confirmation Page. [IAUC 7758, 2001 November 21]
A. Hale, Cloudcroft, NM, reports that this comet showed a 0'.8
coma and total visual magnitude 12.7 on Nov. 22.09 UT (0.41-m
reflector). Additional astrometry and preliminary
parabolic orbital elements appear on MPEC 2001-W53. [IAUC 7760,
2001 November 23] The comet reaches perihelion in late December, at
1.05 AU, but will not become much brighter than at present. The latest
elements show that it is in a Halley type orbit with period 76 years.

A/2001 WS1 (LINEAR)
A/2001 WS1 (LINEAR) is an asteroid, of 17th magnitude, discovered by LINEAR
on November 17.07. With a period of 4.92 years, the orbit is typical of a
Jupiter family comet. It was at perihelion at 1.03 AU in late October.
[MPEC 2001-W36]
A/2001 WU1=1979 WN8 (Palomar-LINEAR)
A/2001 WU1 (Palomar-LINEAR) is an asteroid, of 18th magnitude, re-discovered
by LINEAR on November 18.22 and originally found at Palomar on 1979 November 24.
With a period of 5.56 years, the orbit is typical of a
Jupiter family comet. It will reach perihelion at 1.35 AU in early June 2002.
[MPEC 2001-W38]
2001 WF2 P/LONEOS
An object identified as asteroidal in early images has been found to show clear
signs of cometary activity. The object was at perihelion in late January at 0.98 AU
and has a period of 5.0 years. It is intrinsically very faint and will fade.

An apparently asteroidal object of 19th magnitude discovered by LONEOS
on November 17.27 and designated 2001 WF_2 (cf. MPEC
2001-W42) has been found to have a well-defined 45" tail in p.a.
320 deg on CCD images obtained on Feb. 13.5 UT by T. B. Spahr with
the 1.2-m reflector at Mount Hopkins. Following notification by
Spahr, C. W. Hergenrother also found a 27" tail in p.a. 320 deg and
a stellar central condensation on a 1500-s co-added R-band image
taken with the Catalina 1.54-m reflector. [IAUC 7827, 2002 February 13]

2001 X1 LINEAR
R. Huber, Lincoln Laboratory, Massachusetts Institute of
Technology, reports the discovery by LINEAR of a comet on images
taken on Dec. 13.44 that show a
bright core surrounded by a diffuse coma (comet's magnitude given
as 16.5-17.0) and exhibiting a tail at least 95" long in p.a. 295
deg. CCD observations on Dec. 14.1 UT by R. Stoss and P. Geffert
(Starkenburg Sternwarte, 0.45-m f/4.4 reflector) reveal a well-
condensed coma with a thin tail 5' long in p.a. 300 deg (m_2 =
16.5). CCD images taken in twilight and poor seeing by A. C.
Gilmore (Mount John, 1.0-m f/7.7 reflector) on Dec. 14.6 show the
object as diffuse (m_1 = 14.6-15.1) with a broad, faint fan tail 1'
long in p.a. about 315 deg. [IAUC 7774, 2001 December 14]. The comet
was around 15th magnitude visually.

Brian Marsden notes on MPEC 2002-F19 [2002 March 18] that the "original" and
"future" barycentric values of 1/a are +0.02285
and +0.001659 (+/- 0.000042) AU**-1, respectively. These values show that
the comet is not a new one from the Oort cloud.

2001 X2 P/Scotti
J. V. Scotti, Lunar and Planetary Laboratory, reports his
discovery of a 19th mag comet on CCD images taken with the 0.9-m Spacewatch
telescope on December 14.44, noting a coma diameter of 5" and a tail 0'.40 long in
p.a. 283 deg (and m_2 = 22.7). Confirming observations were made
at Klet by J. Ticha, M. Tichy, and P. Jelinek, who reported a 8"
coma and a faint westward tail. [IAUC 7775, 2001 December 14]. The
latest orbit shows that the comet is of short period
(7.3 years), with perihelion at 2.5 AU in 2001 October. It will fade.
2001 X3 P/LINEAR
R. Huber, Lincoln Laboratory, Massachusetts Institute of
Technology, reports that a 20th mag object discovered by LINEAR on Dec. 7.08
was found to be diffuse on Dec. 17 (with prediscovery LINEAR data
back to Sept. 10). G. Hug, Eskridge, KS, reports that the object
is probably diffuse on CCD images taken on Dec. 19.1 UT (red mag
17.2-17.8). [IAUC 7778, 2001 December 19] The comet has a period of 6.4
years, with perihelion at 1.6 AU. It will fade.

C. Hergenrother, Lunar and Planetary Laboratory; and K.
Muraoka, Kochi, Japan, suggested a link between comet 11D (last
seen in 1908) and P/2001 X3 (cf. IAUC 7778) -- a linkage confirmed
at the Minor Planet Center and by S. Nakano (Sumoto, Japan). The
orbital elements below are by Nakano (from 43 observations,
1908-2001, mean residual 0".8; nongravitational parameters A_1 =
+0.13 +/- 0.01, A_2 = -0.0134 +/- 0.0007). The comet was not found
in 1963 despite a prediction by B. G. Marsden (IAUC 1838, 1839,
1840). More recent predictions were made by Marsden and Sekanina
(1971, A.J. 76, 1142), by Nakano (Comet Handbooks for 1989, 1995,
and 1996, Oriental Astronomical Association; and NK 686), and by
Muraoka (Comet Handbook for 2001, OAA). The indicated correction
to Nakano's 2001 prediction (1998, NK 686) is Delta(T) = +3.4 days.
[IAUC 7779, 2001 December 20] The comet was listed amongst those due to
return in my predictions for 2001 in the BAA Journal for December 2000.

2001 X8 SOHO
A non Kreutz comet discovered by Alexander Mimeev on December 12 in
real-time C2 images. [IAUC 7797, 2002 January 19] Studies by Maik
Meyer show that it forms a triplet with 1997 L2 and 2001 E1.
A/2001 XQ (LINEAR)
A/2001 XQ (LINEAR) is an asteroid, of 15th magnitude, discovered by LINEAR
on December 6.16. It was at perihelion at 1.04 AU in mid December.
[MPEC 2001-X24] With a period of 6.87 years, the orbit is typical of a
Jupiter family comet. It approached to 0.53 AU of Jupiter in 1983, which made
small changes to the orbit.
A/2001 XU (NEAT)
A/2001 XU (NEAT) is an asteroid, of 18th magnitude, discovered by NEAT
on December 7.45. With a period of 4.93 years, the orbit is typical of a
Jupiter family comet. It will reach perihelion at 0.41 AU in early February.
It is a PHA, possibly coming as close as 0.005 AU, but on this occasion
only gets to within 0.22 AU. [MPEC 2001-X28]
A/2001 XL16 (Spacewatch)
A/2001 XL16 (Spacewatch) is an asteroid, of 21st magnitude, discovered by Spacewatch
on December 10.13. With a period of 5.73 years, the orbit is typical of a
Jupiter family comet. It will reach perihelion at 1.50 AU in mid January.
[MPEC 2001-Y44]
2001 Y1 P/Helin-Lawrence
This periodic comet, first observed in 1993, has been recovered by T Oribe at
the Saji observatory. It will reach perihelion at the end of 2002.

On 2001 Dec. 25, S. Nakano (Sumoto, Japan) reported that T.
Oribe had apparently recovered comet P/1993 K2 (= 1993 XI = 1993l)
the night before (December 24.86) with the 1.0-m reflector at the Saji Observatory.
The position was within 2" of the prediction by B. G. Marsden on
MPC 34423 (ephemeris on MPC 43696). No information was provided
about the object's appearance other than m_1 = 19.5. The comet has
now been independently reported by K. Sarneczky and Z. Heiner in
2002 Jan. 11 data obtained with the 0.6-m Schmidt at Piszkesteto,
at m_1 = 20, but again with no information about the appearance.
These observations confirm a tentative single-night detection by C.
W. Hergenrother and D. Means of an object of stellar appearance (in
an 840-s co-added exposure) at the comet's expected position a year
ago with the Steward Observatory's 2.3-m reflector at Kitt Peak.
[IAUC 7790, 2002 January 14]

Further to IAUC 7790, K. Sarneczky reports that his 300-s
unfiltered CCD images taken on Jan. 11.2 UT show a diffuse, 8" coma
and a faint, narrow, 13" tail in p.a. 283 deg. [IAUC 7792, 2002 January 15]
Further to IAUC 7790, T. Oribe reports that his CCD images
taken on 2001 Dec. 24.86 UT show a 0'.15 coma and an 8" tail in
p.a. 295 deg. [IAUC 7794, 2002 January 17]

2001 YX127 P/LINEAR
An object previously reported as asteroidal by LINEAR has been shown to have
cometary characteristics. It is distant and faint, and will fade from 20th
magnitude. It has a period of 8.5 years and a perihelion distance of 3.4 AU.

An apparently asteroidal object of 20th mag discovered by LINEAR
on December 17.32 and designated 2001 YX_127 (cf. MPS
47220, MPO 24028) has been found to have a broad, fan-shaped
extension in p.a. 100 deg on CCD images obtained on Feb. 14.2 UT by
T. B. Spahr with the 1.2-m reflector at Mount Hopkins. Co-added
CCD R-band images taken at about the same time by C. W.
Hergenrother with the Catalina 1.54-m reflector show a 7" coma and
a broad tail 8" long in p.a. 100 deg. [IAUC 7828, 2002 February 14]